I was 16 at the time. Chemistry class. Under severe time constraint to finish an experiment requiring sulfuric acid and H2O. With only 10 minutes left until dismissal, I had accidently poured acid and H2O in two seperate, unmarked containers. I could have used pH paper to to see which was which, but there was no time. I took one flask, swished the contents in my mouth, knowing sulfuric acid would probably taste sour. But luckily I grabbed the right one, and live today to tell this tale.